1. Field of the Invention
This invention relates to two-lever implements, and more particularly, to shears pivotally interconnected and having an ergonomic handle configuration.
2. Description of the Prior Art
In the past, conventional scissors have been constructed with a small loop on an upper lever to accommodate a user's thumb and a large loop connected to the bottom lever to accommodate several or all of a user's fingers. The user's hand when using these conventional scissors resembles a lobster claw. This lobster-like hand positioning does not allow all of the muscles in the hand to be properly utilized and often does not allow a user to easily provide enough force to cut through thick, heavy or strong materials. These scissors mainly require a user's fingers to pull up the bottom lever toward the upper lever to cut a material. Since a user's fingers are weak compared to the remainder of the hand, a user is quickly fatigued. Also, if a user must use a conventional scissors over long periods of time, the user can experience discomfort and develop a repetitive motion disorder, such as carpel tunnel syndrome.
In an effort to increase the comfort to a user and allow the user to more easily cut an object, shears have been developed with a fixed upper lever engageable with a user's thumb and a freely rotatable bottom lever so that as the two levers are brought together to cut an object, the bottom lever rotates and the fingers engaged therewith naturally roll over so that a not quite-closed fist is formed with the thumb that is engaged with the fixed upper lever.
Although these shears are more comfortable to use, extended and prolonged use can still cause a user to develop a repetitive motion disorder because the shears still require a user's fingers to pull the bottom lever upward to the top lever. Additionally, the handle of these shears with the freely rotatable handle are not symmetrical and are designed to be used with either a right hand or a left hand, but not both.
The freely rotatable handle of these shears make these shears adjustable and does not easily allow precise cuts through light materials because the free finger rotation on the bottom handle often causes the shears to cut off-line. Additionally, the freely rotating handle makes it difficult for a user to maintain a controlling grip on the shears, which will cause the shears to fall out of a user's hand and cause personal injury or damage.